Propeller control mechanism for adjustable and reversible pitch propellers



y 1940- c. R. WASEIGE ,207,042

- PROPELLER CONTROL MECHANISM FOR ADJUSTABLE AND REVERSIBLE PITCHPROPELLERS Original Filed April 25, 1935 6 Sheets-Sheet 1 I //P w #5 //5July 9, Mil

' C. R. PROPELLER CONTROL MECHANISM FOR ADJUSTABLE WASEiGE ANDREVERSIBLE PITCH PROPELLERS Original Filed April 25-, 1955 6Sheets-Sheet W ND Q as m W awnMw 51mm.

July 9, 1940. c. R. wAsElGE PRO?ELLER 'CONTRQL MECHANISM FOR ADJUSTABLEAND REVERSIBLE PITCH PROPELLERS Original Filed April 25, 1935 6Sheets-Sheet 5 Ill/I C. R. WASEIGE PROPELLER CON 2,207,042 TROLMECHANISM FOR ADJUSTABLE AND REVERSIBLE PITCH PROPELLERS Original FiledApril 25 1935 Jul 9, 1940.

6 Sheets-Sheet 51 54 55 9 '56 56 y 1940- c. R. WASEI'GE 2,207,042

PROPELLER CONTROL MECHANISM FOR ADJUSTABLE AND REVERSIBLE PITCHPROPELLERS 6 Sheets-Sheet 5 Original Filed April 25. 1935 Illa y 1940-c. R. \NASEEGE 2,207,042

- PROPELLER CONTROL MECHANISM FOR ADJUSTABLE AND REVERSIBLE PITCHPROPELLERS Original File d April 25, 1935 6 Sheets-Sheet 6 IllIIIIIIIIIIIIIIIIIIIIIIII CHARLES IBM Mama MAME/6'15 Attorneys.

Patented July 9, 1940 UNITED, STATE s PATENT OFFICE I PROPELLER CONTROLMEcnANIsM FOR ADJUSTABLE AND REVERSIBLE PITCH PROPELLERS Charles RaymondWaseige, Rueil', France 2 Claims.

My invention relates to airscrew propellers with variable and reversiblepitch used on air crafts, of the type described and claimed in myco-pending application Serial No. 18,139, filed on 5 the 25th of April,1935, of which the present application is divided out.

The'main object of my .invention is to provid connections between thepitch varying and re.- versing gear, its control means, the propellerdriving engine and the control means of the latter, in order to makesome of them dependent on the other or others in some predeterminedoccurrences Witha view to reduce as much as possible the attentionrequired from the operations to 15 be made by the pilot.

This and other objects and advantages of my invention will appearthereafter from the description given below by way of example of twoembodiments of my invention and this description 20 should be read withthe understanding that the form, construction and arrangement of theseveral parts may be varied within the limits of the claims heretoappended, without departing from the spirit of the invention asexpressed in said claims. It is for instance to be understood that whilem invention will be fully described in detail with reference only to oneparticular type of propeller where the driving power required for thisvariation and reversal is furnished by the propeller driving engine, itis also applicable to aerial propellers with variable and reversiblepitch of any other type where the driving power is furnished by thepilot or by an auxiliary motor, electric or other.

In the annexed drawings:

Fig. 1 is a diagrammatic view, showing a propeller with variable pitch,in which the mechanisms for slow variation and for pitch reversalcomprise a common source of power and a speed- "-changing device.

Fig. 2 is a diagrammatic view of a propeller with variable pitch whichemp1oys,.as a source of power for the variation of the pitch, thepropeller 4 driving engine itself.

Fig. 3 is a partial diagrammatic view of a form of the controls whichcan be employed, chiefly in the case of the propeller shown in Fig. 2,as 'well as the connections between the controls.

Figs. 4a and 4b are similar to Fig. 3 but show' another part of thecontrols and'their connections.

Fig. 5 relates to a device for the automatic control of the mechanismfor the slow variation of the speed.

tric motor- I which is supported in such way as to participate in therotation of the propeller,

andit is thus supplied by means of conducting rings 2 which are coaxialwith the propeller and work against fixed brushes, or inversely.

The said motor is connected with the propeller blades 4 by driving gearcomprising a speedchanging device 5, which in this case is aspeedchanging device having two ratios, of the type containing asecondary shaft H on which are keyed gear wheels Ill and H2 respectivelyin mesh with a gear wheel H3 keyed on the motor shaft H4 and with a gearwheel H loose on a shaft H6 .on which is secured a spur gear wheel 6engaging a gear wheel 1 coaxial with the propeller and formed in onewith a set of conical teeth 8 engaging conical teeth 9 mounted on thesupports ll] of the blades on the shaft H6 is slidably keyed a clutchmember lll adapted to alternately engage a cooperating clutch member H8keyed on the motor shaft H4 or a, clutch member H9 secured to the gearwheel H5.

The control of'the speed-changing device 5 is effected by means ofrod-and-link gear of any kind, comprising a member which is coaxial withthe propeller and rotatable with. the latter, but which is movablelengthwise, and herein, this consists of a grooved ring ll co-operatingwith a member which is held against rotation but is movable lengthwise,in this case, a fork ii. A fork I20 engages the slidable clutch memberIll to alternately bring it into engagement with the clutch member H8 orH9.

The operating of the fork l2 will thus permit the use of either of thetwo ratios of transmission of the speed-changing device 5, thusaffording a rapid change of pitch, which is preferably used forreversing the pitch, oron the,contrary, for a slow variation of thepitch, and the change of direction for the pitch variation can beobtained for instance by reversing the motor by means of a usualreversing switch under automatic or manual control.

The embodiment shown in Fig. 2 is a particular embodiment ofpitch-varying mechanism comprising differential gearings adapted to bewhose support can be coupled to or uncoupled braked by means of aservo-motor using fluid under pressure, such as oil.

Herein, there are mounted concentrically with the propeller shaft fourdrums I5, I6, I I, I8 which are loose on their bearings, and co-operatewith brakes I9, 20, 2|, 22. The adjacent drums i1,l8 are connectedtogether by a set of gearing having a negative ratio, 1. e., a gearingsuch that the from the propeller shaft, as to rotation, by means of anysuitable clutch device 25, for instance of the tooth type; the saidplanetary pinion is engaged on the one hand with a set of teeth on thedrum l6, and on the other hand with the drum H by means of aspeed-reducing device which herein consists of a worm portion 26 locatedon the drum l1 and engaging a worm-wheel 21 keyed to v a shaft 28 whichis at right angles to the propeller shaft and carries another worm 29(see Fig. 4b) engaging a suitable wheel 30 keyed to the shaft of thesaid planetary pinion. The drums l5--l6 are also connected together Weset of'gearing having a negative ratio, employing herein for thispurpose a pinion 3i engaging external and internal sets of teeth locatedon the respective drums i5--|5, said pinion being keyed to a shaft 32operating in bearings mounted on the casing of the propeller, thusrotating together with the latter. The movement of rotation of thepinion 3| on its axis is transmitted to the several blades by the shaft32 and a mechanism to be further described.

It will be noted that when noneof the drums are braked, the whole ofthis mechanism will rotate as a unit together with the propeller shaft,.without any internal movement. If one of the drums i5 and I6 is braked,and if the support of the planetary pinion 24 is not secured, as torotation, to the propeller shaft, the pinion 3! will rotate on its ownaxis, in one orthe other direction depending upon which one of the saiddrums is braked, and this will vary the pitch to a greater or lessdegree. On the other hand, the drums IT and I8 continue to operate withthe same movement of rotation as the propeller, and the support of theplanetary pinion 26 has the speed which is suitable for the conditionsnow prevailing.

When one of the drums |1l8 is braked, and when the support of theplanetary pinion 24 has been connected, as to rotation, with thepropeller shaft by means of the clutch 25, this sets up a relativemovement (in one or the other direction, according to the drum which isbraked) of the drum !6 and the support of the planetary pinion 24 and ofthe devices 21 to 30. Hence, through the medium of the speed-reducingparts 26 to 29, the planetary pinion 24 will turn on its own axis,

. in one or the other direction, and this movement the planetary pinion24, will be usedfor the gradual variations of the pitch.

The movement of the pinion 3| itself and the movement of its shaft 32may be-transmitted to the differentb-lades 4 by any suitable means.Herein, this transmission is advantageously obtained by the use of apinion 34 which is mounted on the end of the shaft 32 and engages agearwheel 35 coaxial with the propeller shaft, thus actuating anepicycloidal speed-reducing device comprising a planetary pinion rollingon a fixed base 36 concentric with the propeller shaft, mounted on aneccentric part 35a of the wheel 35 and having a second set of teeth3611, also eccentric, which engages a set of teeth 31 coaxial with thepropeller shaft and rotating together with a bevel pinion engaging abevel gear 9 formed on the base of the propeller. This device ispractically irreversible.

To actuate the pointer of the pitch indicator, not shown, there isprovided herein a shaft 32 on which is keyed a gear wheel .43 in meshwith teeth provided on the drum It. The shaft 42 carries a conical gearwheel forming one sunwheel of adifierential mechanism it the othersun-wheel of which is driven from the propeller shaft through gearwheels 45. Shaft 52 is journaled in bearings internally carried by thestationary casing 46. The planet-carrier of the differential mechanismis secured on a shaft 41 connected to the pitch indicator. The gearwheels 45 are designed in order that the two sun wheels of thedifferential mechanism M are rotated at the same speed when the drum itrotates at the same speed as the propeller shaft, i. e., when none ofthe brakes I9 to 22 is applied; so that the planet-carrier and its shaft41 remain motionless. As soon as a brake is applied and produces arelative rotation between this propeller shaft mechanism 44 are nolonger rotated at the same speed so that the planet carrier will rotateat a speed depending upon that of this relative rotation and drives thepitch indicator.

Fig. 3 shows the hand lever 50 for controlling the pitch-reversingmechanism. This lever is connected by a rod 5!, or like connectingmember, Figs; 3 and 4a with a device controlling servomotors 52 soarranged as to separately throw on the brakes l9 and 20. In Fig. 4a isrepresented two servo-motors, one being disclosed in detail and theother represented in outline form only to render the disclosureperfectly clear. Each servo-motor, (Fig. 4a) only one of which need bedescribed, operates by fluid under pressure, and comprises for eachbrake a cylinder and a fluid distributing valve mechanism preferablyadapted to supply fluid at full rate at all times except when completelycut off. For this purpose, the two valves 53 and 54 for admission andexhaust of the fluid are oppositely disposed and between their discs islocated the end of a lever 55 mounted on a shaft 56 which carries twoother levers 51 and 58 which are urged together by a spring 59. One ofthese levers, 58, is keyed to the shaft 56, the other lever beingloosebetween two stops secured to the shaft and situated on the respectivesides of the extended part of the lever 58, and thus the lever 5'! willturn abruptly in one or the other direction under the action of thespring 59 when it proceeds beyond the said extended part. The two levers51 are-connected together by rod-and-link gear or the like and thus thetwo valves 53 can be closed simultaneously, but only one of the valvescan be opened at a time. Herein. the rod-and-link gear consists of atwo-arm pivoting lever 60; to .one arm is pivoted a link 6| having aslot 62 in which is engaged a stud mounted on one of the levers, 51; tothe other arm is pivoted a link 63, pivotally mounted on one arm of therod 5|, which is bent at right angles, the other arm of the rod, whichis pivoted to the said reversing lever 50 having a slot 64 in which isslidable a stud pertaining to the other lever 51. Thus the wholemechanism ,can have three definite positions, that is, a middle orneutral position in which both valves 53 are closed, and the two valves54 open and two end positions in which one of the valves 53 is openwhilst the other is closed.

In each cylinder 52 is accommodated a piston 52a to be urged against areturn spring 5217 by the fluid pressure. Each piston rod. 52a extendsout of the corresponding cylinder 52. and the outer rod portions areprovided respectively with racks 52c, 52d in mesh with pivoted toothedsectors 52e, 52 connected through cranks 52g, 52h to ,the brakes I910,respectively, to actuate said brakes.

Consequently, when the hand-lever is moved either way from its neutralposition, this will effect the abrupt opening of one of the valves 53,according to the direction of the displacement of the hand-lever, thusthrowing on the corresponding brake. Theautomatic stopping of thereversal by the release of the brake is effected, in this apparatus, bymeans of two cams 65 and 66 corresponding to two predetermined values,positive and negative, of the pitch, said cams being positively operatedby the mechanism of the pitch indicator, and one or the other cam,according to the position of the hand-lever 50, will act upon the lever60 in order to bring the lever 51 of the valve 53 into a position ofunstable equilibrium,

' beyond which the spring 59 will effect the instantaneous closing ofsaid valve 53 and the opening of the valve 54, as well as the return ofthe rod-and-link gear and the reversing lever 50 into the neutralposition herein represented, in which both valves 54 are open and thetwo brakes l9 and 20 are released.

Further the reversing lever 50 is herein connected with the device forthe control of the supply of carburated mixture to the propeller drivingengine through a'rod- 67 (Fig. 3) pivoted at one end to the said lever59, and at the other end to a pivoting cam 58 which acts upon anarticulated joint BE located between two rods T0ll. one of which, it, isconnected with the engine throttle lflb and the other, ll. with thehandlever .72 for the control of this throttle the joint 69 is madeelastic by an elastic or resilient spring arranged to urge and hold therods IO-H in a predetermined angular position. Said means may consistfor instance in a rubber sleeve 690. the external face of which isadhered to the inner face of a metal sleeve 69b carried by one of therods 70,1! while the inner faceof said rubber sleeve 69a is adhered tothe external face of the stud 69c carried by the other of said rods l0,H. The connection between the rod 61 and the pivoted cam howeverprovides for some lost motion in order that the cam will not turn whenthe hand-lever 5B is moved from its neutral position into the positioncorresponding to the positive value of the pitch. On the contrary, whenthe lever 50 is moved into its other position, the cam 68 is turned, andit thus moves the joint 69 when this is located on its path, which takesplace for positions of the hand-lever" corresponding to a small openingof the engine throt tle. The movement of the joint 69 thuseflects anincreased opening of the engine throttle without any displacement of thethrottle control lever 12. When the lever 50 returns to its neutralposition, the levers Ill-H return into the position shown in Fig. 3.

As the mechanism for the slow variation of the propeller pitch is alsoactuated, in this apparatus. by a servo-motor 15 using fluid underpressure, there is interposed in the conduit supplying the fluid underpressure, a valve 16 adapted for quick opening and closing, themechanism for this purpose being, for instance, of the type of themechanism 5'l-5859. This mechanism is controlled by a rod 11 urged by aspring 18, Fig. 3, in such way that the valve 16 will be continuallyurged toward open position, said rod ,being pivoted at the other end toa pivoted lever l9 located in the path of the cam said cam is connectedwith the throttle control lever 12, and its outline is such that the rod11 will be maintained, against the action of the spring 18, in aposition in which the valve Hi-is closed, whilst the hand-lever T2 is inthe position in which the openingof the engine throttle is below apredetermined value.

In order to avoid all improper working, it is necessary that themechanism for the slow variation of the pitch should not be actuatedwhile the pitch-reversing mechanism is'in action. For this purpose, usemay be made of a control device similar to the control of the mechanismfor slow variation of the pitch, by the throttle lever, and it ispreferable to employ a device, as herein represented. For this purpose,the lever 19 cooperates with. a cam 8| mounted on the reversing lever50, and the outline of the cam is such that it is only when the lever 50is in the neutral position that the lever 79 may be brought by thespring 78 into' the position corresponding to the opening of the valvel6.

Furthermore, in the construction shown in Fig. 2, it is necessary, inorder that the reversing mechanism may operate, that the support of theplanetary pinion 24 shall be released. For this purpose, a connection ismade between the reversing lever 50 and the movable part of the clutch25, and thus the displacement of the handlever 50 from its middleposition will effect the release of the said support. Herein, thisconnection makes use of the said cam BI and the lever-l9 whose angulardisplacements are trans mitted by suitable rod-and-link gear 82, or likedevice, to a pivoted fork 83 which moves the said movable partlengthwise, by means of a-grooved collar 84 coaxial with the propellershaft. The clutching, which might be effected by the pilot at will, isherein automatically efiected by the the slow'variation of the pitch, insuch way that this mechanism cannot be actuated when the pitch has anegative value, is shown in Fig. 6, in which the control of thereversing mechanism is employed for this purpose. The cam 8|, which cutsout the mechanism for slow variation during the operating of thereversing mechanism, is herein divided into two parts am and Nb; thepart 8la is provided on the hand-lever 50 to turn therewith, whilst thepart Bib is connected with the same with a certain angular play or lostmotion, for instance by a tenon 86 provided on the hand lever 50 andengaged in a groove Bl in the said member 8"). These various members areset in such a way that when the hand-lever 50 in its middle or neutralposition as illustrated in Fig. 6 one side of the tenon 86 is inengagement with the right hand end of the groove 81 while the part 8";is in a position allowing free operation of the mechanism for slowprogressive variation of the pitch. When the control lever 50 is movedaccording to the arrow f (Fig. 6) from its neutral position into theposition corresponding to the negative pitch, the tenon 86 will thusturn along with it thepart Nb of, the cam,

- gressive variation of the pitch is thereby brought which then bearsupon the lever 19 and likewise as in Fig. 3 actuates the cut-out deviceE5 to I9, as well as the mechanism 82-85 which controls the clutch 25and the mechanism for slow proout of operation. When the handle 50returns to the neutral position, the tenon 86 will slide back in thegroove 81 without moving the memher 8"), which thus continues to holddown the lever 19 and the left side of the tenon 86 comes 'hand lever 50has now come into engagement with the lever I9 and holds down the latterso that the mechanism for the slow variation of the pitch remains keptout of action. When the hand-lever returns to the neutral position, thetenon 86 moves in the groove 87 without turning the cam piece Qlb whichremains in its initial iosition but turned out of engagement with thelever 19 which is thus allowed to be swung upwards by the spring 18,whereby releasing the mechanism for the slow variation of the pitch asdescribed above with reference to Fig. 3.

Fig. 3 also shows an example of the construction of a device adapted toprevent the racing of the engine when the propeller pitch comes to zeroand when the engine throttle is well open.

For this purpose, the present apparatus comprises a rotating cam 88connected by a suitable transmission means 861:, including adifferential, with the mechanism 42 controlling the pitch indicator. Thesaid cam actuates a lever 89 pivoting on a stationary axle 89a, and alsopivoted to the rod-and-link gear '|li1ila controlling the enginethrottle. It will be noted that the position of the lever 89 thusdepends upon the position of the engine throttle, and when the latter issufficiently closed, the cam 88 can rotate without meeting the lever 89when the pitch passes through the zero value. On the contrary, when thethrottle is well open, the lever 89 comes upon the path of the cam 88and the cam willthus act upon the lever at the time when the pitchpasses through the zero point, thus momentarily closing the enginethrottle.

The same effect may be obtained by the cooperation of levers or camsmounted respectively on the throttle control lever and on the reversinglever, and adapted to act upon the throttle control in such way as toreduce the supply of carburated mixture to the engine for certainpredetermined relative positions of the reversing lever and the throttlelever.

Fig. 5 shows a devicefor the automatic con-- trol of the mechanism forthe slow variation of the pitch according to the engine speed. Herein,

the centrifugal governor 90 is driven by the englue and it controls thevalve-gear of the servomotor 15 by means of the lever 9|. The tension ofthe spring 92 can be regulated while running, by the displacement of oneof its supports consisting of a nut 93 mounted on a threaded rod 94which can be rotated by suitable driving means, herein comprising thebevel gear wheels 95--96, the latter wheel being driven by the pinion9'! engaging a rack 98 actuated by a retating cam 99- secured to agear-wheel I00 engaging a like wheel I M rotatable by means of ahand-lever I02 together with a'pointer I03 moving over a dial I04graduated in numbers of revolutions. Thus the displacement of thehandlever I02 regulates the speed-of the engine by causing a variationof the pitch, and the governor 96 will then keep this speedautomatically constant by suitably actuating the mechanism for the slowvariation of the pitch according to the conditions of flight, whether ona level, or for riseor descent, or the like.

Fig. 5 also shows a form of construction of a device for limiting thepossible variation of the propeller pitch to a range comprised betweentwo extreme positive values. Said device herein consists of two stopsI05 located on the path of the hand-lever I02, in such way thatthislever cannot assume a position outside of the sector which is thusdefined and which corresponds to engine 'speeds on either side of thenormal working different positions of throttle lever 12, while stoppingthe action of the automatic mechanism for. the slow variation of thepitch.

Fig. 4b shows a form of construction of a hand control I ii] forbringing the propeller blades in line with the direction of the wind, inthe case in which the oil pressure becomes reduced, or in case of otherdefective action. The said control H0 herein consists of a device of aknown type operating by cable and acting directly upon a lever IHcontrolling a brake shoe 22, and when this latter is applied, it willcause a gradual reduction of the pitch.

The general operation of the devices above described is as follows:

When I move the control lever 50 from the position shown in Fig. '7 tothe left to the position indicated by the sign I pull on the rod SI andmove the latter to the left, whereby turning the lever 60 contrary tothe clockwise direction and the lever 51 to the right through the mediumof the lever 6|. The spring 59 then urges the lever 55 to turn contraryto the clockwise direction, whereby opening valve 53 and enabling valve54 to be closed by its return spring. Fluid under pressure is thusadmitted in the cylinder 52 and moves the piston 52a carrying the rack520 which turns the sector 52e contrary to the clockwise direction andthereby applies the brake I!) through the crank 52g. The pitch reversinggear is thus set in operation and the pitch is rapidly reversed from apositive to a negative value, as above described with particularreference to Figs. 2, 3 and 4. It will be noted that during thismovement of the rod 5i to the left the stud of the lever 57 of theservo-motor connected to the brake 20 slides idly in the slot 64 of therod 5| so that this movement of the rod 5| is without effect on thisservo-motor.

At the same time the displacement of the control'lever to the leftproduces a clockwise rotation of the pivoted cam 66 through the mediumof the connecting rod 67 and in turn the cam 68 will stretch out theknee 69, whereby opening the throttle 10b through the rod Ill.

The operation of the pitch varying gear causes the shaft 67 to rotate asabove described and the latter in turn rotates the cam 88 through theshaft 88a. This cam 88 will thus come into engagement with the lever 89and turn it contrarily to the clockwise direction when the pitch isapproaching the value zero. This rotation of 'the lever 89 istransmitted by the connecting rod 10a, to the throttle 70b which is thusbrought to the position corresponding to the slow speed running of theengine, and the rod '10 is moved to the right. As the control lever 12has not been moved and is held fixed this motion of the rod 16 willproduce a bending of the knee 69 whatever may be the position of the cam68 but as soon as the cam 88 releases the lever 89 this elastic joint 69will resume its former position, whereby opening again the throttle 10b.

If'the lever 12 is initially in a position such that it holds thethrottle 10b in the position of slow speed running of the engine, itwill readily be understood that the lever 89 will be held by theconnecting rod 10a out of the path of the cam 88.

The shaft 41 rotates also the cams 65, 66 cone nected to said indicator.At the same time where the pointer of the pitch indicator comessubstantially in register with the mark on the dial, i. e., when thepitch has a predetermined negative value, the cam 65 comes intoengagement with the pivoted lever 60 and swings it back to the positionof Fig. '7, whereby pulling back the rod 5| and the control lever 50 totheir initial neutral position, closing valve 53 and opening the exhaustvalve 54. The return spring 52b will then move back the' piston 52a toits rest position, whereby releasing the brake l9 and stopping theoperationof the pitch reversing When I move the control lever 50 to theright, I push on the rod 5i and operates the lever 51 directly pivotedto said rod; this lever 51 in turn operates the valves of thecorresponding servomotor 52 in the same manner as above described withreference to the other servo-motor 52. The

latter remains inoperative since the link 6'! is moved to the left andthe slot 62 slides on the corresponding lever 51 without actuating thelatter. The brakes 20 are thus applied by the operating servo-motor52'and the pitch value is reversed from a negative to a positive pitchvalue until the cam 66 rotated from the pitch indicator comes intoengagement with the pivoted lever 60 and moves it back to its neutralposition together with the link 5!, its associated'lever 59 and thecontrol lever 50, whereby stopping the reversing gear. The operation ofthe cam 88 during this pitch reversal from a negative value to apositive value is exactly the same as during the inverse pitch reversal.

It will be noted that the motion-of the control lever 58 to the rightdoes not operate the cam 68 owing to the lost motion connection betweenthem.

I claim:

1. Control means for a variable pitch propeller provided with anautomatic pitch varying mechanism adapted to slowly and progressivelydecrease and increase the pitch in dependence on the rotating speed ofthe propeller and. a pitch reversing mechanism adapted to far morerapidly reverse the pitch from a positive value to a negative value .andvice versa at the will of the pilot, said control means including meansoperable from the pilot to selectively cause operation of saidmechanisms, means adapted to automatically control the fuel supply tothe engine in dependence on the pitch value, and a further means adaptedto vary the fuel supply and operatively connected to said means operablefrom the pilot to be actuated thereby.

2. Control means for a variable pitch propeller provided with anautomatic pitch, varying mech-.

anism adapted to slowly and progressively decrease andincrease the pitchin dependence on the rotating speed of the propeller and a pitch of thelatter and to said locking means in order that said locking means willlock the automatic pitch varying mechanism as long-as the pitchreversing mechanism is in operation.

' CHARLES RAYMOND WASEIGE.

